TL;DR: Mosaic 0.13 introduced the blue links because it had to distinguish visited and unvisited links. Just paraphrasing article here, not sure about it's accu

TL;DR: Mosaic 0.13 introduced the blue links because it had to distinguish visited and unvisited links. Just paraphrasing article here, not sure about it's accuracy since many have pointed out its inaccuracies.